#include <bits/stdc++.h>

#define in read()
#define fi first
#define se second
#define pb push_back
#define rep(i, x, y) for(int i = (x); i <= (y); i++)
#define per(i, x, y) for(int i = (x); i >= (y); i--)

using namespace std;

using pii = pair < int , int >;
using vec = vector < int >;
using veg = vector < pii >;
using ll = long long;
using db = double;

int read() {
    int x = 0; bool f = 0; char ch = getchar(); while(!isdigit(ch)) f |= ch == '-',ch = getchar();
    while(isdigit(ch)) x = x * 10 + (ch ^ 48),ch = getchar(); return f ? -x : x;
}

const int N = 5010;

int a[N], n, m, s;
ll ta[N];
db ans;

int main() {
#ifndef ONLINE_JUDGE
    freopen("1.in","r",stdin);
#endif
	n = in, m = in, s = in;
	rep(i, 1, n) a[i] = in, ta[i] = ta[i - 1] + a[i];
	rep(i, 0, n) { // 1 ~ i : 0
		rep(j, i + 1, n + 1) { // j ~ n : m
			ll lef = s - 1ll * (n - j + 1) * m;
			if(lef > (j - i - 1) * m || lef < 0) continue;
			db res = (ta[n] - ta[j - 1]) * m;
			if(j - 1 > i) res += (ta[j - 1] - ta[i]) * (1. * lef / (j - 1 - i));
			ans = max(ans, res);
		}
	} printf("%.8lf\n", ans);
}
